Method of forging



Sept. 8, 1936. s. sPATTA 2,053,975

` METHOD OF FORGING voriginal Filed Feb. 21, 195o y Y y Patented Sept.8, 1936 UNITED STATES PATENT oFFlc METHOD or rename George Spatta,Buchanan, Mich., assignor to Clark Equipment Company. Buchanan, Mich., acorporation of Michigan 9Claiml.

'I'his invention relates to a method of forging a heated tubular blankby a series of endwise upsetting operations which thicken the walls ofthe blank and stretch them to form a collar of cylindrical shape andhaving internal and external diameters greater than the internal andexternal diameters respectively of the blank. The operations also form aplanar flange of the free end of this collar and in a plane normal tothe axis of the blank. The operations thus performed may conveniently beused as a step in the process of forming an axle housing such as is setout in my. co-pending application Serial No. 416,537, filed December 26,1929, issued as Patent No. 1,926,353 on Sept. 12, 1933, although themethod herein disclosed is not to be specically limited to this purpose.

In my co-pending application, Serial No. 430,206, led February 21, 1930,(Case 22), issued as Patent No. 2,027,406 on January 14, 1936, of whichapplication the instant case is a division, I disclose a machine capableof performing the forging method herein set forth. While the use of amachine of the type disclosed in the parent application is preferable inthe carrying out of the instant process, my improved method is notlimited to such a machine and may, if desired, be performed by othermechanical arrangements.

My invention will be best understood by reference to the accompanyingdrawing in which a preferred embodiment of it is diagrammatically shown,and in whichz- Figure 1 is -an elevation view, partly in Sectio of ablank and forming punch and die used in the first step of my process;

n'Figure 2 is a similar view showing the work at in a suitableclampingmember which holds itl against longitudinal displacement withthe heated end of the blank projecting into a stationary die member 3 ofsuitable design.

A punch carried on a suitable ram is aligned with the die 3 and adaptedto be brought into reg- (Cl. 2li-15G) istration therewith. The punch hasa shoulder 4 which engages the outermost end 5 of the heated blank, asthe die advances axially of the heated blank, and collapses the metal ofthat end into the section of the blank that is disposed within thestationary die member. In Figure 1, the end section 5 of the blank isshown by a dash dot lines and these lines indicate the shape and size ofthe blank at the beginning of the first step in the instant process.

After the punch 2 has completed its travel into the die 3, the metal inthe end section 5 of the blank has been forced inward radially of theblank to form a thickened wall section indicated generally at 6 inFigure 1. 'Ihe walls of the blank I have been broken away in this figureto better indicate the shape of this thickened wall section 6. It willbe noted that the inside diameter of the thickened portion 6, whichconforms to the outside diameter of the nose 1 of the punch, ismaterially less than the inside diameter of the original blank I, andthat the outside diameter 8 of the section 6 is slightly greater thanthe outside diameter of the original blank. 'I'he larger diameterportion 8 is tapered into the outer surface of the blank wall I by ataper 9 located adjacent the innermost end of the thickened wall section6.

Upon the completion of this operation, the blank is unclamped and movedto a second die into which the thickened wall section 6 is projected.This die also has a vcooperating punch adapted to register with it andis equipped with a shoulder I0 adapted to engage the extreme end I I ofthe thickened wall section 6 of the blank. In Figure 2 I have shown theblank at the completion of this second step in the present process. Thedie I2 is shaped so that when the punch I3 registers with it thethickened wall section 6 of the blank I is forced outward to form aflange I4 on the end of the blank. The nose I4' of the punch is of adiameter slightly greater than the internal diameterA of the section 6,so that simultaneously with the axial shortening of the tube by thisoperation, the walls of the section 6 are stretched outward radially atthe axially outer end of the thickened portion Ii so that their insidediameter is increased. The die I2 also is shaped to increase theexternal diameter of the blank to form a collar I5 located adnt thehange Il. The thickness of the end man of the blank at the point of thehangs Il is obviously further increased by the operation of the tools inthis second step of my process. It is to be noted that during theoperation in the second set of dies. the metal of the inside of thethickened portion l. and'l at the axially inward part thereof, that is.the metal at the point la, is forced axially rearward or inwardlongitudinally of the blank. This produces a thickened.

portion tc on the inside of and immediately to the rear oftbe\previously thickened portion l. lhe thickness of the material oftheblank adjacent the thickened hange Il is greatly'increased in thatthe outer diameter has been increased by the formation of the collarportion Il and the inner diameter has been decreased by the formation ofthe metal at the point Ic.

At the completion of this second step, the work is again unclamped andbrought into registration with another die and rie-clamped in placein'that die. As will be seen in Figure 3. this die is provided with acooperating punch I6 which has a shoulder II which engages the free endI8 of the flange Il of the blank and with a tapered nose which spreadsthe walls of this section Il to increase their internal diameter. As thepunch is brought into registration with the work, the metal in the hangeI0 and in the sub collar I5 is forced outward radially into engagementwith the die Il-to thereby form a cylindrical collar 20 whose externaldiameter is materially greater than the external diameter of the blank Iand whose internal wall is tapered as at 2l to join it with thelthickened wall section 22 formed inwardly of the blank I by the nose ofthe punch. The punch also forms a flange 23 whose external diameter ismaterially larger than the external diameter of the collar 2l and whoseparallel hat faces Il and 2l are disposed in planes normal to the axisof the blank I. It is to be noted that the metal for forming thethickened wall section I2 is obtained by pushing the metal 8c backaxially of the blank, that is, in a direction parallel with the axis ofthe blank.

Upon the completion of this third step in the process, the blank isremoved and its opposite end heated and that end then broughtsuccessively into engagement with the punches and dies herebeforedescribed to form a similar collar and hange on that end;

As is well understood by those skilled in the art of forging, themaximum amount of metal how that can be made in one step is definitelylimited. and if this amount is exceeded, the work is buckled or brokenand is therefore defective. By proper design of the dies and punchesused in the process, Il am able to move a maximum amount of metal byeach step of the process without damage to the work. Obviously thisreduces the number of separate steps necessary to fabricate the work andfurthermore permits completion of the several steps of the process withone heating of the work, that is, during the interval during which it iscooling to a temperature too low for proper forging.

The method, while primarily intended as a step in the process of formingan axle housing set out in the teachings of my above mentionedco-pending application Serial No. 416,537, is obviously not limited tothis general process and may be used for the Purpose of forming a flangeupon the end of any tubular blank.

Having thus complied with the statutes and shown and described thepreferred embodiment of my invention. what I consider new and desire tovhave protected by Letten Patent is pointed out in the appended claims.

What is claimed is:-

l. The method of forging the end of a metal tube which comprises.thickening the end of the tube radially by forcing it inward axially.then forcing the thickened portion out radially and in axially at theaxial outer portion of the thickened part and forcing the metal inaxially at the axially innermost portion of the thickened part, toincrease the thickness of the tube at a point spaced axially inward ofthe part hrst thickened.

then anling the axially outer portion of the thickened part of the tubeand increasing both the thickness and the diameter of the portion -ofthe tube in back of the hange.

2. The method of forging the end of a metal tube which comprises,thickening the end of the tube radially by forcing the metal inwardaxially 20 and radially, then forcing the thickened portion out radiallyand in axially at the axial outer portion of the thickened part andforcing the metal in axially at the axially innermost portion of thethickened part, to increase the thickness of the tube at a point spacedaxially inward of the part first thickened,y each of the forcingoperations being along the entire periphery of the tube simultaneously,then forcing the end portion of the thickened part of the tube radiallyoutward to form a hange. l

3. The method of forging the end of a metal tube which comprises,simultaneously forcing the metal along the entire periphery at the endof the tube outward radially to form a flange, and simultaneouslyforcing the metal on the outside of the tube axially rearwardly tothicken the tube rearwardly beyond the rear face of the hange.

4. The method of forging the end of a metal tube which comprises forcingthe metal at the end of the tube outward radially by a series ofoperations to form a flange having front and rear faces, each of theoperations forcing the metal simultaneously along the entire peripheryof the end of the tube, and during the series of operations gatheringmetal along the outside of the tube rearwardly of the rear hange face tothicken the tube portion at the rear of the hange.

5. 'I'he method of forging the end of a metal tube which comprises.thickening the end of the tube by decreasing the internal radius of thetube. then forcing the metal at the end of the thickened part radiallyoutward to form a hange with a thickened portion of the tube axiallyrearward of the flange, then flattening the hange axially to increaseits radius, and forcing the metal outward axially back of the hange toincrease the internal radius of the tube back of the hange whilemaintaining the thickness in excess of the original tube thickness.

6. The method of upsetting and hanging end of a tubular arm whichcomprises heating said end, subjecting said end while heated to a seriesof'endwlse upsetting operations comprising initially gathering metal tothicken said end, and subsequently haring and hanging said thickened endto produce a thickened radial flange joined to said arm by an enlargedthickened bearing seat portion.

'1. The method of upsetting and hanging the end of a tubular arm whichcomprises heating said end. successively subjecting said heated end tothree endwise upsetting operations to form a thickened end expanded intoa bearing seat, and a thickened radial ilange at the outer end of said yseat, and controlling the area of the die surfaces 9. The method ofilanging a tubular member which comprises subjecting said member toendwise upsetting to increase the wall thickness adjacent one endthereof, expanding the thickened portion radially, and forcing the endof said thickened portion outwardly to form a thickened radiallyextending ange joined to said member by a thickened bearing seatportion.

GEORGE sPA'i'rA. 1o

